.floatImg {
    float: right;
}

* {
    font-family: "DejaVu Sans", Arial, Helvetica, sans-serif;
}

html {
    font-size: 100% /* or 62.5% or whatever you like, it doesn't matter, it's just a browser fix, however "rem" units will be based on that value, so make it confortable for calculations */
}

body {
    font-size: 0.85em; /* That is your text's default font size. Here i chose 12px */
}